Inspired by the low-cost computing power of the Raspberry Pi, a team at the University of Southampton has used the ARM-based Linux computer-on-a-board as a building block for a low-cost supercomputer—racked and stacked using Lego blocks. And they’ve published a step-by-step guide for anyone interested in creating their own Raspberry Pi high-performance computing “bramble."

Led by Professor Simon Cox, with Lego expertise lent by Cox’s 6-year old son James (who spent the summer learning to program on the Raspberry Pi using Python and MIT's Scratch), the team used 64 Raspberry Pi computers, each equipped with a 16-gigabyte SD card to construct a functioning computing cluster for under £2,500 (a bit over $4,000)—not including the Ethernet swtiches used to connect the nodes.

Enlarge/ A pair of Raspberry Pi compute nodes in their Lego racking enclosure.

“As soon as we were able to source sufficient Raspberry Pi computers,” Professor Cox said, “we wanted to see if it was possible to link them together into a supercomputer. We installed and built all of the necessary software on the Pi starting from a standard Debian Wheezy system image and we have published a guide so you can build your own supercomputer.”

The software for “Iridis-Pi”—named after Southampton’s Iridis supercomputer—uses a free implementation of the Message Passing Interface and code written in Python to distribute parallel computing tasks. The first test run on the cluster: calculating the value of Pi.

"Supercomputer" I don't know about, but definitely useful to learn distributed computing basics. Also, I would sadly not classify Lego as low-cost. *sighs whistfully at wishlist of parts to order from BrickLink*

Awesome project. The potential for scalability for something like this would be very interesting ("well, just throw a dozen more Pi's at it"). I'm curious what the "$ vs compute power" line looks like for "bunch of Raspberry Pi's networked together" compared to more traditional HPC solutions.

The price is right about the cost of 4 fairly powerful desktop PCs as well. This is a good platform for learning how to manage distributed computing resources though, and a lot cheaper than most options. He even used fairly cheap lego bricks (by lego standards), mostly just 1xN bars and flat plates.

But which consumes more electricity? 64 Pis or 4 of your desktop? One could use a setup like this for a low-power system for crunching stuff in parallel without a major hit to the temperature of the room, or the electric bill.

It's pretty well agreed upon that R-Pis are not competitive with X86 hardware in either performance per watt or in performance per buck (except for very small values of "buck"), if you're looking to get actual work out of them. But getting 64 R-Pis for this kind of project is far more affordable than 64 cores of X86 hardware (consider that the R-Pi comes with its own motherboard included at only $35 per core), so long as you're only using it as a teaching tool for parallel computing or such.

But which consumes more electricity? 64 Pis or 4 of your desktop? One could use a setup like this for a low-power system for crunching stuff in parallel without a major hit to the temperature of the room, or the electric bill.

If the guy who said 2 watts/board is anywhere close to accurate (I have no idea if it is, probably not), then it's actually remarkably efficient in watt/performance.

For the sake of really quick comparisons, I'm going to pretend all processors can do the exact same amount of work/per clock. (Yes, I am aware this is idiotic, just go with it)

One 3.5ghz quad i7 is equal to 20 Pi's. Given a TDP of 120 watts for the i7, each Pi board can eat 6 watts and still maintain performance/watt.

But which consumes more electricity? 64 Pis or 4 of your desktop? One could use a setup like this for a low-power system for crunching stuff in parallel without a major hit to the temperature of the room, or the electric bill.

It's hard to say, best estimate I can find puts a pi at 3.5W without peripherals, these require ethernet connectivity, but not sure how much that adds, .5W? So maybe 224-256W. The i7-3770K has a TDP of 77W, 4x = 308W ignoring other overhead. So the 64Pi likely sucks less juice, but pretty confident it's not a legitimate comparison due to performance, guessing that you wouldn't really need 4 of my desktop to equal the 64Pi, but maybe I'm wrong. Still, fun.

Oh no it's not. That's why we broke away from England and her Tyranny, we want our math without an "s", and we want to pronounce aluminum how it should be pronounced. This whole freedom thing was just a by product.

Oh no it's not. That's why we broke away from England and her Tyranny, we want our math without an "s", and we want to pronounce aluminum how it should be pronounced. This whole freedom thing was just a by product.

Oh no it's not. That's why we broke away from England and her Tyranny, we want our math without an "s", and we want to pronounce aluminum how it should be pronounced. This whole freedom thing was just a by product.

Funnily enough...

There is (or at least was) some IUPAC agreement that the Brits would start spelling sulphur with an f, and the Yanks would start putting the second i in aluminium[1]. Needless to say, I now see books and articles published in the UK talking about sulfur, and ones from the US still talking about aluminum. In Canada, of course, you use alternate spellings throughout.

[1] To be consistent with the names of a lot of other elements[2][2] Except sul(f|ph)ur...[3][3] And argon...[4][4] And... oh Monty Python skit!

Oh no it's not. That's why we broke away from England and her Tyranny, we want our math without an "s", and we want to pronounce aluminum how it should be pronounced. This whole freedom thing was just a by product.

Funnily enough...

There is (or at least was) some IUPAC agreement that the Brits would start spelling sulphur with an f, and the Yanks would start putting the second i in aluminium[1]. Needless to say, I now see books and articles published in the UK talking about sulfur, and ones from the US still talking about aluminum. In Canada, of course, you use alternate spellings throughout.

[1] To be consistent with the names of a lot of other elements[2][2] Except sul(f|ph)ur...[3][3] And argon...[4][4] And... oh Monty Python skit!

It's like armour/armor, that's how I tell if a book is Brit (or an ex-colony thereof), or American. It actually strikes me as funny that so many of the other ex-colonies stick with the UK spelling, while we Americans (as usual) just spell shit how we please.